Epitaxially coated semiconductor wafer and process for producing it

Abstract

A semiconductor wafer with a front surface and a back surface and an epitaxial layer of semiconducting material deposited on the front surface. In the semiconductor wafer, the epitaxial layer has a maximum local flatness value SFQR_max of less than or equal to 0.13 μm and a maximum density of 0.14 scattered light centers per cm². The front surface of the semiconductor wafer, prior to the deposition of the epitaxial layer, has a surface roughness of 0.05 to 0.29 nm RMS, measured by AFM on a 1 μm×1 μm reference area. Furthermore, there is a process for producing the semiconductor wafer. The process includes the following process steps: (a) as a single polishing step, simultaneous polishing of the front surface and of the back surface of the semiconductor wafer between rotating polishing plates while an alkaline polishing slurry is being supplied, the semiconductor wafer lying in a cutout of a carrier whose thickness is dimensioned to be 2 to 20 μm less than the thickness of the semiconductor wafer after the latter has been polished; (b) simultaneous treatment of the front surface and of the back surface of the semiconductor wafer between rotating polishing plates while a liquid containing at least one polyhydric alcohol having 2 to 6 carbon atoms is being supplied; (c) cleaning and drying of the semiconductor wafer; and (d) deposition of the epitaxial layer on the front surface of the semiconductor wafer produced in accordance with steps (a) to (c).

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]Applicant claim priority under 35 U.S.C. 119 of German Patent Application No. 199 38 340.5 filed Aug. 13, 1999. This Patent application is a division of and Applicants claim priority under 35 U.S.C. 120 of U.S. patent application Ser. No. 09 / 617,192 filed Jul. 14, 2000 now abandoned.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a semiconductor wafer with an epitaxial coating on a front surface which has improved flatness and a reduced number of light scattering centers on the epitaxial layer, and to a cost-effective process for producing it. Semiconductor wafers of this type are suitable for use in the semiconductor industry, in particular for the fabrication of electronic components with line widths of less than or equal to 0.13 μm.[0004]2. The Prior Art[0005]A semiconductor wafer which is intended to be suitable in particular for the fabrication of electronic components with line widths...

AI Technical Summary

Benefits of technology

[0041]After the performance of the epitaxial coating of at least the front surface of the semiconductor wafer, which is particularly preferably composed of silicon, particularly preferably with silicon, a semiconductor wafer according to the invention is present. Thus, this wafer has a hydrophobic surface and can be supplied in this form for further processing for the purpose of producing integrated components. However, it is possible, although not absolutely necessary within the scope of the invention, to hydrophilize the wafer surface in order to provide protection against contamination. That is to coat t...

Problems solved by technology

The process takes place without carrying out a cost-intensive final polishing step, which adversely affects the geometry of the s...